Captain Archibald Robertson of the Royal Engineers was at the Battle of Brandywine on September 11, 1777. For five days after the battle, General Howe rested his troops on the battelfield. During this time, Captain Robertson prepared a map and narrative key. The original map is part of 4000 military maps in King George III’s Collection at the Royal Library, Windsor Castle.

The Robertson map measures 104.1 x 74.2 cm with a scale of 1:6000. It is in the Royal Collection, Windsor Castle under RCIN 734026. The modern roads and uppercase black and white letters were added by Roy Najecki in 2003. He also added the comments to the narrative after speaking with Tom McGuire. The original is RCIN 734026.A. Map changes done in red by Ralph Housman in 2012 more accurately reflect unit positions shown on the original map.

Ralph Housman carefully scrutinized the map and narrative. His comments:

After reading the narrative and studying the map, the first point of concern is the absence of any part of the battle that was described by American General Sullivan and by various accounts describing the actions of the 3rd Virginia Regiment, some of whom were posted in an Orchard near Street Road and later, behind the stone wall at Birmingham Meeting. The narrative also omits the action near Street Road described by Hessian Captain Johann Ewald in his diary. (Diary of the American War, A Hessian Journal, Translated and edited by Joseph P. Tustin). Also, there is no mention of the stiff resistance put up by the Americans at Sandy Hollow.

Quoting from the narrative: “After advancing to the high Ground mark’d A [Osborne’s Hill] in the Plan, the Enemy were observed at Birmingham Meeting, but moving and unsettled—The Army was ordered immediately to advance and form as in the plan B. The Rebels then fell back and took the position expressed in the Plan C, …”

Robertson states that the Rebels fell back when the British advanced to B. There are 9 position B’s, the leading one’s being about 0.5 km north of Street Road. It appears that Robertson is claiming that the Rebels at Birmingham Meeting offered no resistance and as soon as the British advanced to B, 0.5 km north of Street Road, the Americans fell back to C (in the field south of Meetinghouse Road, South of Wylie Road and the south end of Sandy Hollow, all without a battle?)

Quoting again from the narrative: “… the first Battn. of Light Infantry charged and took five Pieces of Cannon in their Front. When the 4th Brigade which followed the Rear of the first Battn. Light Infantry gained the Hill G …”

This is in the center of paragraph 2. No concept of time is given. Now the British are in control of Hill G. No mention of the fierce defense described by Sullivan.

From Amory’s Life of Sullivan, p. 49: “This hill commanded both the right and left of our line, and, if carried by the enemy, I knew would instantly bring on a total rout and make a retreat very difficult. I therefore determined to hold it as long as possible, to give Lord Stirling’s and General Stephen’s divisions, which yet stood firm, as much assistance from the artillery as possible, and to give Colonel Hazen’s, Dayton’s and Ogden’s regiments, which still stood firm on our left, the same advantage, and to cover the broken troops of my division, and to give them an opportunity to rally and come to our assistance, which some of them did, and others could not by their officers be brought to do anything but fly. The enemy soon began to bend their principal force against the hill, and the fire was close and heavy for a long time, and soon became general. Lord Stirling and General Conway, with their aides-de-camp, were with me on the hill, and exerted themselves beyond description to keep up the troops. Five times did the enemy drive our troops from the hill, and as often was it regained, and the summit often disputed almost muzzle to muzzle. How far I had a hand in this, and whether I endured the hottest of the enemy’s fire, I cheerfully submit to the gentlemen who were with me. The general fire of the line lasted an hour and forty minutes, fifty-one minutes of which the hill was disputed almost muzzle to muzzle, in such a manner that General Conway, who has seen much service, says he never saw so close and severe a fire. On the right, where General Stephen was, it was long and severe, and on the left considerable. When we found the right and left oppressed by numbers and giving way on all quarters, we were obliged to abandon the hill we had so long contended for, but not till we had almost covered the ground between that and Birmingham meetinghouse with the dead bodies of the enemy.”

Quoting from the narrative(still in paragraph 2): “Light Infantry gained the Hill G, the two Rear Battns. the 33rd and 46th filed off to their left in the Rear of the 5 Companies of the 2nd Battn. of Light Infantry H, who by that time had got upon the Flank of the Rebels, and so facilitated the Charge made by the remainder of the 2nd Battn. of Light Infantry and Chasseurs across the Field I, who drove the Rebels and took their two Pieces of Cannon.”

Apparently without resistance from the “Rebels.” compare the above description with:

The only mention of Rebel resistance between Street Road and Dilworth: “… two Battalions of Light Infantry being a little in Front, … halted in the position E until the two Battalions of British Grenadiers got up to the Rails at F, when they received a heavy Fire from the Rebels in their Front; after crossing the Rails they immediately charged and drove the Rebels before them.”

No mention of any resistance at Dilworth. Then, in Paragraph 3: [We are now well south of Dilworth, near Webb Road]: “The Rebels were discover’d behind the Fence L in Front, with two Pieces of Cannon M, with which they cannonaded the Troops at K,” and, “4th Brigade wheel’d up to their left in the position Q, when a very heavy Fire commenced from Hedges and Woods R where the Rebels had retired, from which they were very soon driven on all sides, but it being by this time almost Dark, …”

Reading this narrative, one is left with the impression that the British drove the Americans back from the Meeting House to well south of Dilworth with little or no resistance, from 4 PM to nightfall, approximately 2 and 1/2 hours (sunset being at 6:15). What in the world were the Americans doing for 2 and 1/2 hours? You would never know from this map and report.

Yes, I believe my first impression was correct. The Robertson map and narrative is heavily biased in favor of the British (not unusual) and something for the King to be impressed by. An accurately drawn map is not evidence of an accurate description of the battle.